/Engine/Source/Runtime/Slate/Public/Widgets/Docking/SDockTab.h
Set Label Suffix. A second text field at the end of the Label that takes precedence and isn't lost when space is restricted
void SetTabLabelSuffix ( const [TAttribute](API\Runtime\Core\Misc\TAttribute)< [FText](API\Runtime\Core\Internationalization\FText) > & InTabLabelSuffix )